Added ability to draw a non-filled rectangle

include/Renderer.h

@@ -37,6 +37,8 @@ Renderer *create_renderer(SDL_Window *window);
 void get_render_output_size(Renderer *renderer, int32_t *w, int32_t *h);
 
 void render_clear(const Renderer *renderer, SDL_Color color);
+void draw_rect(const Renderer *renderer, SDL_Color color, float x, float y,
+               float w, float h);
 void fill_rect(const Renderer *renderer, SDL_Color color, float x, float y,
                float w, float h);
 void render_surface(const Renderer *renderer, SDL_Surface *surface,